Can nutrients be harmful?

Most vitamins and nutrients appear to be safe as supplements, even at levels higher than the Recommended Dietary Allowances (RDAs). However, some can cause problems at higher doses, including Vitamin A, Vitamin D, copper, iron, niacin, selenium, and zinc.

A basic program of vitamin and mineral supplementation should be safe. This would include the following, all taken according to directions on the bottle:

• A multiple vitamin/mineral (without extra iron),

• An antioxidant supplement with several different ingredients, and

• A trace element supplement. There are seven essential trace elements: chromium, copper, cobalt, iodine, iron, selenium, and zinc. Some multivitamins also include trace elements.

Any other program of supplements should be based on discussion with a doctor or nutritionist. Remember that higher price may not mean better quality.